Flexible vacuum package and method of storing a product under vacuum in a package

ABSTRACT

A flexible package for a product and method of storing a product in a package is disclosed. The package includes an inner bag and an outer bag. The inner bag is formed of a flexible material, is arranged to hold a product that degasses, e.g., whole bean coffee, and includes a one-way valve. The outer bag is also formed of a flexible material and encloses the inner bag, forming a gas space therebetween. The gas space is in communication with the ambient atmosphere via at least one communicating passageway. Gas may vent through the one-way valve into the gas space and from there through the at least one passageway, with the outer bag providing a smooth aesthetically pleasing appearance notwithstanding changes in pressure and/or temperature to which the package is subjected.

CROSS-REFERENCE TO RELATED APPLICATIONS

This utility application claims the benefit under 35 U.S.C. §119(e) of Provisional Application Ser. No. 61/756,162 filed on Jan. 24, 2013 entitled Flexible Vacuum Package and Method of Storing a Product Under Vacuum in a Package. The entire disclosure of the provisional application is incorporated by reference herein.

BACKGROUND OF THE INVENTION

This invention relates to flexible packages and more particularly to valved flexible packages for coffee and a method of storing coffee in a vacuum package whereupon the package maintains a smooth aesthetically pleasing appearance even under conditions of changes in atmospheric pressure and/or temperature.

Various types of stand-up flexible packages are known for storing beans, flakes, granular, powders and the like. One example of such a flexible package is a side gusseted bag typically used for packaging roasted coffee. The side gusseted bag is made from a flexible packaging laminate composed of various layers of plastic films, metal foils and papers bonded together using adhesives and extrusions. The flexible packaging laminate is generally printed or labeled for the package contents and other consumer information. The flexible packaging laminate is normally produced as sheeting wound onto a roll or rolls which is used to form many packages. The flexible package is formed from the laminate using conventional equipment such as pre-made bag machines, vertical form-fill-seal machines, horizontal form-fill-seal machines and other well-known equipment. These machines fold a sheet of the flexible laminate and seal together some of the edges and leaving a filling mouth. The package is then filled through the mouth and then sealed across the filling mouth to complete the package.

The formed and filled side gusseted package generally takes the shape of a parallelepiped or 6-faced polyhedron though at times the package top may also take the form of a triangular prism.

Roasted coffee is highly sensitive to degradation by oxidation and must be packaged using material with a high barrier to oxygen. The problem is that roasted coffee liberates a large volume of carbon dioxide and other gasses as a result of the roasting process. The hard shell of the coffee bean slows the gas generation rate and therefore gasses can still be liberated for weeks after roasting. It is therefore very important to package roasted coffee immediately after roasting in airtight high oxygen barrier containers fitted with a means of releasing gasses from the container without allowing ingress of air/oxygen. Thus, typically flexible vacuum packages for coffee include a one-way valve for degassing the package. One such degassing valve is disclosed in U.S. Pat. No. 3,595,467 (Goglio). Other examples of one-way valves for packages are also found in the following U.S. Pat. No. 3,595,467 (Goglio); U.S. Pat. No. 4,576,285 (Goglio); and U.S. Pat. No. 4,705,174 (Goglio) and many similar one-way valves are currently on the market. Packages including these valves allow gas pressure to escape from the package when the internal package pressure exceeds the atmospheric pressure by a predetermined value. In particular, many of these valves operate at approximately 0.1 psi. Thus, when the pressure inside of the package exceeds the atmospheric pressure by 0.1 psi the valve opens and releases the excess pressure. The valve should close again prior to reaching equilibrium pressure.

Typically a number of such flexible coffee-containing packages are placed into cartons for shipment. For example, six packages containing twelve ounces of coffee each are placed into a carton tight enough to prevent excessive movement during shipment.

In the case of packages containing freshly roasted coffee, it has become common practice to package and store coffee prior to shipment long enough (several weeks for whole bean coffee) to allow the product to substantially complete the degassing process. During shipment coffee packages can be subjected to atmospheric pressure changes due to altitude changes and/or temperature changes. For example, when atmospheric pressure is reduced the gasses inside of a coffee package will be forced out of the one-way valve. When the same package is subjected to increased atmospheric pressure at lower altitude the one-way valve prevents ingress of air, thus causing the lower air pressure package to collapse and appear to be under vacuum. If the coffee has substantially completed degassing the package will remain with a vacuum like appearance (sometimes referred to as being “bricked”). A “bricked” package may be seen as aesthetically objectionable to the consumer.

In my copending U.S. Provisional Patent Application Ser. No. 61/709,561, filed on Oct. 4, 2012, entitled Flexible Packaging System And Method Of Use To Eliminate Valved Coffee Bag Vacuumization Due To Change In Atmospheric Pressure, whose disclosure is incorporated by reference herein, there is disclosed and claimed a packaging system and a method of packaging coffee in valved bags which prevents bricking irrespective of changes in atmospheric pressure. In particular, that invention basically entailed providing a system comprising a plurality of primary flexible packages, a secondary package and a rigid container. Each of the primary flexible packages includes a one-way, degassing valve to enable gasses produced by the coffee therein to exit without air entering the primary package through the degassing valve. Each of the degassing valves of the primary flexible packages have a predetermined operating pressure at which the gasses produced by the coffee are enabled to pass out of the package through the valve. The secondary package is formed of a flexible material and holds a plurality of the primary flexible packages therein. The secondary package includes a one-way pressure release valve having an appropriate opening pressure to control gas release during the shipment of the coffee packages so that the secondary package internal pressure never drops below the operating pressure of the primary package degassing valves. The rigid container is arranged to hold the secondary package with said primary coffee packages therein to protect the same during shipment and storage.

My prior U.S. Pat. No. 4,835,037 (Beer); and U.S. Pat. No. 4,835,037 (Beer) and U.S. Pat. No. 4,734,292 (Goglio) disclose flexible packages designed to mask the vacuum appearance of vacuum packaged products. Those packages basically comprise an inner bag and an outer bag separated by an air space which vents to the ambient atmosphere to provide a smooth aesthetically pleasing appearance for the outer bag. The packages of those patents are under vacuum from the time they are packaged and do not undergo package changes during distribution. Moreover, they do not contain a one-way valve and are not useful for packaging coffee that is actively degassing.

The invention disclosed in my above noted pending application overcomes many of the disadvantages of the prior art and is suitable for its intended purposes to prevent vacuum packages from bricking However, a need still exists for a primary vacuum package for coffee that includes a degassing valve and that in and of itself provides a smooth aesthetically pleasing external appearance notwithstanding changes in atmospheric pressure and/or temperature to which the package may be subjected. The subject invention addresses that need.

SUMMARY OF THE INVENTION

One aspect of this invention entails a flexible package for a product, e.g., whole bean coffee, held under vacuum in the package. The package basically comprises an inner bag and an outer bag. The inner bag is formed of a flexible sheet material and comprises a hollow interior in which the product is located, a wall panel bounding the hollow interior of the inner bag and a one-way valve located on that panel and in communication with the interior of said inner bag where the product is held under vacuum. The outer bag is formed of a flexible sheet material and comprises a hollow interior in which the inner bag is located, a wall panel having a seal line and bounding the hollow interior of the outer bag. The seal line comprises at least one passageway in fluid communication with the interior of the outer bag and the ambient surroundings of the package. The one-way valve is arranged to enable gas within the interior of the inner bag to vent through the one-way valve into the interior of the outer bag, whereupon the gas may vent to the ambient surroundings through the at least one passageway, with the outer bag having and maintaining a smooth aesthetically pleasing appearance notwithstanding changes in pressure and/or temperature to which the package is subjected.

Another aspect of this invention is a method a method of storing a product, e.g., whole bean coffee, in a package under vacuum. The method entails providing a package comprising an inner bag and an outer bag. Each of the bags is formed of a flexible sheet material. The inner bag is formed of a flexible sheet material and comprises a hollow interior, a wall panel bounding the hollow interior of the inner bag and a one-way valve located in the panel in communication with the interior of the inner bag. The outer bag is formed of a flexible sheet material and comprises a hollow interior, a wall panel having a seal line and bounding the hollow interior of the outer bag. The seal line comprises at least one passageway in fluid communication with the interior of the outer bag. A product, such as whole bean coffee, is introduced into the interior of the inner bag and is held under vacuum therein. The inner bag is disposed within the interior of the outer bag, whereupon gas within the inner bag may vent through the one-way valve into the interior of the outer bag and through the at least one passageway in the outer bag to the ambient surroundings, with the wall panel of outer bag providing a smooth aesthetically pleasing appearance notwithstanding changes in pressure and/or temperature to which the package is subjected.

DESCRIPTION OF THE DRAWING

FIG. 1 is an isometric view of one exemplary embodiment of a coffee package 20 comprising a valved inner bag and an outer bag constructed in accordance with this invention;

FIG. 2 is an isometric view similar to FIG. 1 but showing a portion of the package (i.e., the outer bag) being broken away;

FIG. 3 is a vertical (longitudinal) sectional view of the package of FIG. 1 taken along line 3-3 of FIG. 1; and

FIG. 4 is a horizontal (transverse) sectional view of the package of FIG. 1 taken along line 4-4 of that figure, but prior to the package being filled with coffee.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the various figures of the drawing wherein like reference characters refer to like parts, there is shown at 20 in FIG. 1 one exemplary embodiment of a package constructed in accordance with this invention for holding a product which degasses, e.g., coffee 10. The package 20 basically comprises an outer flexible bag 22 and an inner flexible bag 24. The package is formed by applying adhesive in pre-patterned areas along selected portions of webs or sheets of flexible material to form the package, sealing the sheets together, and thereafter folding the package into the desired shape and sealing its bottom ends and top ends along respective seal lines and sealing its vertical back seam by the application of energy, such as heat.

The outer bag 22 basically comprises a hollow body having a front wall panel 22A, a rear wall panel 22B and a pair of side gussets 22C and 22D (FIG. 4), with its vertical back seam or fin 22E extending along the length rear panel. The panels 22A, 22B and the gussets 22C, 22D define a hollow interior 28 (FIG. 3) in which the inner bag 22 is located. The inner bag is preferably composed of a flexible material that resistant to the passage of gases such as oxygen, since it will hold the product, e.g., coffee, under vacuum. The inner bag 24 basically comprises a front wall panel 24A, a rear wall panel 24B and a pair of side gussets 24C and 24D, with the seal line or fin of the inner bag being located between contiguous portions of the rear panel 22B of the outer bag making up its seam 22E. The panels 24A, 24B and gussets 24C, 24D define a hollow interior in which a product, in this exemplary case whole bean coffee 10, is located.

The inner bag 24 is secured to the outer bag along its top and bottom edges and along the vertically oriented back seam or fin 22E by a patterned adhesive 38 (FIG. 3). In particular, the pattered adhesive extends along the entire width of the top 32 of the package except for two areas between contiguous portions of the inner and outer bag to define respective passageways through which air from the ambient atmosphere may flow to enter into the space 28 between the two bags. In particular, as can be seen in FIG. 3 a passageway 34A is located between the top portion of the front panel 22A of the outer bag 22 and the underlying top portion of the front panel 24A of the inner bag 24. In a similar manner, a passageway 34B is located between the top portion of the front panel 22B of the outer bag 22 and the underlying top portion of the front panel 24B of the inner bag 24.

The adhesive securing the inner bag to the outer bag also extends along the vertical seam or fin 22E, except for two areas between contiguous portions of the inner and outer bag to define respective passageways through which air from the ambient atmosphere may flow to enter into the space 28 between the two bags. In particular, as can be seen in FIG. 4 a passageway 36A is located between the edge portion of the rear panel 22B of the outer bag 22 forming the fin 22E and the underlying edge portion of the rear panel 24B of the inner bag 24. In a similar manner, a passageway 36B is located between the other edge portion of the rear panel 22B of the outer bag forming the fin 22E and the underlying edge portion of the rear panel 24B of the inner bag 24.

In the exemplary embodiment shown a conventional one-way degassing valve 26 is mounted on the front panel 24A of the inner bag, but could be mounted on other portions of the inner bag, if desired. In particular, in the embodiment shown in the drawings hereof, the valve 26 is mounted on the inside surface of the front panel 24A and thus is within the interior of the inner bag where the coffee 10 is located. The valve 26 could, if desired, be mounted on the outer surface of the panel 24A. In either case, the valve 26 is of any suitable construction, such as disclosed in any of the prior art patents identified above or others that are commercially available, and is arranged to open when the internal pressure within the inner bag 24, e.g., the pressure produced by the degassing coffee, exceeds the ambient pressure outside the package. Typically degassing valves for coffee are set at approximately 0.1 PSI.

With coffee packaged in the package 20 as described above, it may be shipped immediately or it may be placed into storage for shipment at a later date even beyond the time of complete degassing. Whenever the coffee is shipped the package's construction will prevent the exterior (visible portions) of the package from exhibiting the vacuum-like (“bricked” or “pebble”) appearance irrespective of changes in atmospheric pressure and/or temperature to which the package is subjected. The following is an example of the use of the package 20 of this invention to demonstrate how it achieves its desired results irrespective of changes in atmospheric pressure encountered by shipment of a package from a packaging facility to a retail facility. Assume that coffee is roasted in Salt Lake City, Utah and packaged in a package 20, wherein the valve 26 on the inner bag 24 is a 0.1 PSI opening pressure one-way degassing valve. Assume that the package's destination is Sacramento, Calif. and that the coffee is shipped 30 days after roasting and has completed degassing. As is known, Salt Lake City's official elevation is 4,330 feet. Interstate 80 runs between Salt Lake City and Sacramento, crossing the Donner Pass at an elevation of 7,239 feet. Sacramento, Calif., the destination, has an elevation of about 25 feet. During shipment from Salt Lake City to Sacramento the coffee package 20 will experience a low atmospheric pressure of 11.4 PSI during transit and a high atmospheric pressure of 14.7 PSI at the destination. At the Donner Pass, the maximum quantity of gas will have been released and the pressure inside of the package will equilibrate to the atmospheric pressure of 11.4 PSI. During descent into Sacramento, the valve 26 will remain closed as atmospheric pressure increases. In Sacramento, the outside pressure of 14.7 PSI will compress the inner bag 24 and make it appear to be under vacuum, i.e., it will have a bricked appearance, like shown in the broken-away portion of FIG. 2. However, the panels 22A, 22B, 22C and 22D forming the outer bag 22, which are separated from the bricked inner-bag by the gas space 28 therebetween (which is in communication with the ambient surroundings by virtue of the passageways 34A, 34B, 36A and 36B), will still exhibit a smooth aesthetically pleasing appearance, thus masking or hiding the bricked inner bag 24 from view.

It should be pointed out at this juncture, that the package 20 is one exemplary of various types of packages that can be constructed in accordance with this invention. Thus, the size, shape and construction of the package can be changed, providing that the package includes an inner flexible compartment having a wall panel on which a one-way valve is mounted, and an outer flexible compartment separated from the inner compartment by a gas space and with at least one passageway in fluid communication with the gas space and with the ambient surroundings. For example, the package can be a shaped as gusseted package, like shown, or can be a stand-up pouch, or a pillow-shaped package or any other desired shape. Moreover, the at least one passageway communicating with the gas space between the inner and outer compartments need not be formed in any particular location, nor be formed by any particular means, e.g., a non-adhesive area between adjacent adhesive areas as in the exemplary embodiment shown.

Furthermore, while the exemplary package described above focused on vacuum packages, it should be pointed out that such usage is not exclusive. Thus, packages constructed in accordance with this invention are suitable for use both under vacuum and not under vacuum allowing the user to ship product at any time in the degassing process and still end up with a smooth appearance. To that end, both soft and vacuum packages constructed in accordance with this invention if placed on the shelf side-by-side and observe by a consumer the consumer would not be able to visually see a difference

Without further elaboration the foregoing will so fully illustrate our invention that others may, by applying current or future knowledge, adopt the same for use under various conditions of service. 

What is claimed is:
 1. A flexible package for a product held in said package, said package comprising an inner bag and an outer bag, said inner bag being formed of a flexible sheet material and comprising a hollow interior in which the product is located, a wall panel bounding said hollow interior of said inner bag and a one-way valve located in said panel in communication with said interior of said inner bag where the product is held under vacuum, said outer bag being formed of a flexible sheet material and comprising a hollow interior in which said inner bag is located, a wall panel having a seal line and bounding said hollow interior of said outer bag, said seal line comprising at least one passageway in fluid communication with said interior of said outer bag and the ambient surroundings of said package, said one-way valve being arranged to enable gas within said interior of said inner bag to vent through said one-way valve into said interior of said outer bag, whereupon said gas may vent to the ambient surroundings through said at least one passageway, said outer bag having and maintaining a smooth aesthetically pleasing appearance notwithstanding changes in pressure and/or temperature to which said package is subjected.
 2. The flexible package of claim 1 wherein said seal line comprises an adhesive applied in a pattern to form said passageway.
 3. The flexible package of claim 1 wherein said package is a gusseted package.
 4. The flexible package of claim 2 wherein said package is a gusseted package.
 5. The flexible package of claim 1 wherein said package is a stand-up pouch.
 6. The flexible package of claim 2 wherein said package is a stand-up pouch.
 7. The flexible package of claim 1 wherein said inner bag is under vacuum.
 8. A method of storing a product in a package, said method comprising: a) providing a package comprising an inner bag and an outer bag, each of said bags being formed of a flexible sheet material, said inner bag being formed of a flexible sheet material and comprising a hollow interior, a wall panel bounding said hollow interior of said inner bag and a one-way valve located in said panel in communication with said interior of said inner bag, said outer bag being formed of a flexible sheet material and comprising a hollow interior, a wall panel having a seal line and bounding said hollow interior of said outer bag, said seal line comprising at least one passageway in fluid communication with said interior of said outer bag; b) introducing said product into said interior of said inner bag whereupon said product is held under vacuum therein; and c) disposing said inner bag within said interior of said outer bag, whereupon gas within said inner bag may vent through said one-way valve into said interior of said outer bag and through said at least one passageway in said outer bag to the ambient surroundings, with said wall panel of outer bag providing a smooth aesthetically pleasing appearance notwithstanding changes in pressure and/or temperature to which said package is subjected.
 9. The method of claim 8 wherein said product is coffee.
 10. The method of claim 8 wherein said inner bag is under vacuum. 